Exploring the Detection Limits of ERG Oncoprotein in Prostate Cancer Using Different Sample Types Simulating Clinical Specimens

摘要

Using PRISM-SRM, three ERG peptides were detected using purified ERG3 protein spiked into LNCaP cell lysates. Peptide VIVPADPTLWSTDHVR provided the best response, allowing ERG protein detection at the 20 pg level. PRISM-SRM allowed for detection of ERG protein from 10,000 VCaP cells spiked in LNCaP cells (simulating tissue), and from as low as 600 VCaP cells spiked in female urine (simulating urine sediment). ELISA allowed for detection of 50-100 pg of ERG3 spiked in LNCaP lysates; Western blotting and NanoString allowed for detection of ERG from ～10,000 VCap cells spiked in cell mixtures and urine sediments, respectively.